"They are at least proof of the inalienable part played, in the functioning of our complex vision, by sensation as an organ of research. But they have a further interest. They are an illuminating revelation of the inherent character and personal bias of the individual soul who is philosophizing. I suppose to a great many minds what we call "the universe" presents itself as a colossal circle, without any circumference, filled with an innumerable number of material objects floating in some thin attenuated ether. I suppose the centre of this circle with no circumference is generally assumed to be the "self" or "soul" of the person projecting this particular image."